THE FARMER'S MAGAZINE. 



253 



in the river is almost none : it continues in being lost at 

 every step from the right angle to the point of no angle 

 at all, when it entirely ceases. This method must be 

 used in every possible case of adoption, and will prove 

 more generally useful than flood-gates, for the reasons 

 that have been given. 



The alluvial flat which the river traverses will 

 often be bounded by high lands on both sides, that 

 have a hollow ground along the base, and which is 

 often low as the river, or below its level. This 

 situation is often very appropriate for an open cut, into 

 which much water will flow, from the high ground ou 

 one side, and from the flat space between it and the 

 river. In the case of a small drainage, the discharge 

 of the ramitications will open into this cut, which will 

 run a parallel course with the river, and join the cur- 

 rent at a sharp corner, when the river inclines to that 

 side of the valley, and impinges against the high 

 grounds. A flood of the river will stop the current of 

 water in this cut; but the extent of it being capacious, 

 and the flowing of it along with the rivers, will make 

 the damage less formidable than in any other way, as 

 the depth of bottom will be considerably below the 

 level of the small drains. At all events, the backward 

 force will be less than in any other arrangement. 



The descent of rivers is often much accelei'ated, and 

 the discharge of water increased, by cutting off the 

 corners of its course, straightening the line, and thus 

 lowering the level of the water. Where a straight 

 line cannot be got, the rounding of corners will re- 

 ceive the conflict of waters with the obstacles of its 

 course, put the eddying mass into motion, and increase 

 the onward progress. Jetties of stone-work will be 

 required at the sharpest turnings, which being placed 

 to receive the current of water at a sharp angle of inci- 

 dence, will throw it off at a similar angle, and direct it 

 into the mid-stream of the channel, when it will move 

 quicker from the agitation. Very sluggish movements 

 of water in alluvial flats may be accelerated in this 

 way, the level deepened, and a conveying-trunk ob- 

 tained for the small drains. 



The other case of rivers affording an insufficient 

 trimk for the discharge of waters collected from small 

 drains occurs on extensive lowlands, fens, and marshes, 

 through which the streams meander in a devious 

 course in search of the sea, and having little or no 

 onward fall, and the bed raised by the sedimented 

 mud, to or above the level of the surrounding 

 grounds. Embankments are in this case the very 

 first resort, with openings through which may pass 

 the tributary streams that flow from the country 

 on both sides of the river. When these minor streams 

 are of considerable size embankments must confine 

 these waters also, and conduct into the main river. 

 The streams being joined, the same level of waters will 

 be preserved, and the same flow of current will prevail. 

 These collections of water afford a very bad trunk 

 for the purpose of draining ; but modern discoveries 

 have tended wholly to remove the evil. Slanting 

 courses are to be adopted, as has been mentioned, and 

 every outlet sought at which a stream can be intro- 

 duced into the main current. When no outward pas- 

 sage can be found the water collected into the open cut 

 from the small drains is led by the same conductor 

 to the lowest corner of the ground, and immediately 

 bibind the embankment a deep pond is formed, from 

 which the water is raised by the pump of a steam- 

 engine, and thrown into spouts, which convey it over 

 the bank into the river, from whence there is no 

 return. By this means the collected waters are re- 

 duced to the lowest level, and no overflow or stagna- 

 tion ever happens. The mighty power of steam has 

 in this case overcome all perplexities, and has reduced 



into a nutshell the trunk draining of the low lands that 

 are below the level of descent. It is certainly the 

 extreme ajjplication, when all other propositions fail, 

 or are seen to be impossible; and it had better be at 

 first adopted, than after a large expenditure has failed 

 to reach the object. It is a sure agent and an eflectual 

 operation in every case of its power, 



Brooks are a trunk of the same kind as rivers, re- 

 ceiving and conveying waters that have been collected 

 by the smaller curi'cnts. In order to favour the quick 

 passage of the water the courses will, in many cases, 

 require to be deepened and straightened — especially 

 the last — and also widened, where the quantity of the 

 collected waters is found to be too large lor the room 

 that is contained within the banks. The natural chan- 

 nels that have been excavated at random will bo in- 

 sufficient to answer the modern purposes of drainage; 

 widening will be the best alteration, and always with a 

 depth below the bottom level of tlie small drains. 

 When the quantity of water is the largest in the brook 

 its top level should be below the drains, or, at least, not 

 impede the discharge. Allowing waters a wide extent 

 of course is much better than deepening the bed : ex- 

 pansion of the volume diminishes the dejith and, cor- 

 respondingly, its force, and being spread in widtli 

 below the level o*^ the drains, no stoppage can happen 

 from the water rising to the orifices. A wide water- 

 course of medium depth forms the best trunk for drain- 

 ing — the depth has little impinging force against the 

 banks, and any swell of the water is lost in the width 

 of the course. The bed is hollowed in the middle, 

 where the ordinary current may flow, to prevent the 

 wandering of the water from bank to bank, and alter- 

 nately impinging against and tearing the confines of its 

 course. A depth in the centre and a sloping shallow- 

 ness on the sides and below the banks, ou which the 

 flood can spread and roll along, constitutes the most 

 eligible course for all small streams, as brooks and 

 rivulets, always allotting the extent of the bed to the 

 quantity of water that has been found to prevail at all 

 times and occasions. Circumstances may not allow this 

 adoption in the full extent, but the performances of the 

 kind may be made to tend in that direction. The 

 bottom level of the small drains may be on the top 

 of the slope of the side of the course, which the highest 

 flood may never reach, and the opening of the drains 

 never exposed to damage. Gentle elevations of surlaco 

 will readliy allow this arrangement which may be used 

 in many modifications. 



The improvement of brooks, as trunks for draining, 

 is done as for rivers, when the courses run through flat 

 ponds and level countries. The means must be adopted 

 of widening, deepening, and cutting straight the 

 courses and i-ounding the corners, by which to accele- 

 rate the discharge of the water, and quickly re- 

 lieve the small drains of the contents. The top 

 level of the water in the brook must be below the 

 bottom level of the small drains, so that the 

 discharge of the latter is always to be seen, and the 

 highest'flood of the brook must not exclude the view, 

 except for a short time. The ultimate etticacy of 

 brooks as a trunk drain depends upon the main river, 

 of which it is a tributary, at least in the near approaches 

 of its course to the bed of the river. Here the ground 

 is generally flat, and the course of the water may be- 

 come sluggish, and rise to the small drains, when the 

 object becomes apparent of having the river's course 

 sufficient to receive and convey the additional bulk that 

 comes to be admitted. The brook is a river in minia- 

 ture, and must be adapted by the means that have been 

 mentioned to receive and convey the discharge of the 

 smaller drains in the like manner that the river has 

 been altered and improved in its course, to admit and 



